Coloured Aqueous Polymer Dispersions, And Production And Use Of Same

ABSTRACT

The invention relates to a coloured polymer dispersion containing, as main ingredients: (a) a coloured polymer produced by polymerisation of monomer A with monomer B, monomer A being a pigment B which is coated with a polymerisable wax D wherein the polymerisable function is an ethylenically unsaturated group, monomer B being a ethylenically unsaturated compound; (b) at least one non-ionic surface-active additive E based on polyethers and/or polyglycerines; (c) at least one anionic surface-active additive F based on sulfonates, sulfates, phosphonates, phosphates or carboxylates; and (d) water.

Polymer dispersions are employed in numerous applications. For thepurpose of coloring it is possible to use not only dyes but alsopigments. On account of their higher light stability and weatherresistance, pigments are preferred in aqueous applications. In pigmentedsystems, however, problems are presented in particular by the stabilityof the preparation and the fixing on the substrate or in the binder;likewise, the color effect and the gloss are not always satisfactory. Inorder to counter these problems it is prior art to provide pigments withpolar coatings or to stabilize them through additions.

For instance, JP 1999 00 040 329 describes the addition of aself-emulsifying resin in a water-compatible solvent. In the course ofthis treatment a polymer film forms on the pigment surface thatsimplifies the dispersing of the pigment in aqueous systems.

JP 2000 239 392 describes the use of polyurethane/acrylate dispersions.The addition of such polymer dispersions to a pigment dispersionlikewise leads to a polar coating. The pigments are stable in water andsolvent and exhibit good storage stability. Products of this kind arerecommended for use in coatings or inks.

In EP-A-1 614 721, pigments are treated with a polymer made fromhydrophobic and hydrophilic monomers and compounds containing urethanegroups.

EP-A-1 035 178 describes a chemical surface treatment for improvingstorage stability, where the surface of particles of carbon black ismade more polar, by means of oxidation, so that they can be used inink-jet inks.

Stable dispersions can also be generated through the addition ofsurface-active components.

In the case of the processes set out to date, stability and adhesion areoptimized, but there is virtually no improvement in gloss.

Wax coatings are also known for pigments, as in U.S. Pat. No. 5,298,355,for example.

Applied from water, however, preparations of this kind do not produceresistant films. The problem is to find the right balance.Surface-active substances improve the stability but reduce the waterresistance of the applied material; additions of polymer improve thedispersibility and adhesion, but may be disadvantageous with respect tocolor and gloss; waxes give the desired gloss, but are difficult toapply from water.

The problem posed is therefore that of preparing colored, film-formingpolymer dispersions which are storage-stable and produce good adhesion,gloss, color action and weathering resistance.

It has been found that the polymer dispersion below surprisingly solvesthis problem.

The invention provides a colored polymer dispersion comprising asessential constituents

-   (a) a color polymer prepared by polymerizing monomer A with monomer    B, monomer A being a pigment P which is coated with a polymerizable    wax D in which the polymerizable function is an ethylenically    unsaturated group, and monomer B being an ethylenically unsaturated    compound;-   (b) at least one nonionic surface-active additive E based on    polyethers and/or polyglycerols;-   (c) at least one anionic surface-active additive F based on    sulfonates, sulfates, phosphonates, phosphates or carboxylates;-   (d) water.

Preference is given to polymer dispersions characterized by

-   2% to 60%, preferably 5% to 45%, more particularly 8% to 35%, by    weight of component (a),-   0.1% to 15%, preferably 0.1% to 12%, more particularly 0.5% to 5%,    by weight of component (b),-   0.1% to 15%, preferably 0.1% to 10%, more particularly 0.5% to 2%,    by weight of component (c),-   10% to 90%, preferably 10% to 70%, more particularly 10% to 60%, by    weight of water (d),-   0% to 20%, preferably 0.01% to 10%, more particularly 0.1% to 5%, by    weight of typical auxiliaries (e),-   the sum of the weight percentages not exceeding 100% by weight.

In the polymer dispersion of the invention the pigment P may be anorganic chromatic pigment, an inorganic chromatic pigment, a whitepigment, a carbon black pigment or a combination of two or morepigments.

The organic chromatic pigment may preferably be an azo pigment, ananthanthrone pigment, an anthrapyrimidine pigment, a quinacridonepigment, a quinophthalone pigment, a diketopyrrolopyrrole pigment, adioxazine pigment, an indanthrone pigment, an isoindoline pigment, anisoindolinone pigment, an isoviolanthrone pigment, a perylene pigment, aperinone pigment, a phthalocyanine pigment, a pyranthrone pigment, apyrazoloquinazolone pigment, a thioindigo pigment, a triarylcarboniumpigment or a combination thereof.

Examples of pigments P are as follows:

-   azo pigments:-   C.I. Pigment Yellow 12, 13, 14, 16, 17, 26, 74, 81, 83, 97, 106,    113, 120, 127, 151, 155, 174,176,180, 188, 213, 214;-   disazo pigments:-   C.I. Pigment Orange 16, 34, 44, 72, 108;    disazo condensation pigments:-   C.I. Pigment Red 144, 166, 214, 220, 221, 242, 262;-   C.I. Pigment Yellow 93, 95, and 128;-   C.I. Pigment Brown 23 and 41;    anthanthrone pigments:-   C.I. Pigment Red 168;    anthraquinone pigments:-   C.I. Pigment Yellow 147, 177, and 199;-   C.I. Pigment Violet 31;    anthrapyrimidine pigments:-   C.I. Pigment Yellow 108;    quinacridone pigments:-   C.I. Pigment Orange 48 and 49;-   C.I. Pigment Red 122, 202, 206, and 209;-   C.I. Pigment Violet 19;    quinophthalone pigments:-   C.I. Pigment Yellow 138;    diketopyrrolopyrrole pigments:-   C.I. Pigment Orange 71, 73, and 81;-   C.I. Pigment Red 254, 255, 264, 270, and 272;    dioxazine pigments:-   C.I. Pigment Violet 23 and 37;-   C.I. Pigment Blue 80;    flavanthrone pigments:-   C.I. Pigment Yellow 24;-   indanthrone pigments: C.I. Pigment Blue 60 and 64;-   isoindoline pigments: C.I. Pigment Orange 61 and 69;-   C.I. Pigment Red 260;-   C.I. Pigment Yellow 139 and 185;-   isoindolinone pigments: C.I. Pigment Yellow 109, 110, and 173;-   isoviolanthrone pigments: C.I. Pigment Violet 31;-   metal complex pigments: C.I. Pigment Red 257;-   C.I. Pigment Yellow 117, 129, 150, 133, and 177;-   C.I. Pigment Green 8;-   perinone pigments: C.I. Pigment Orange 43;-   C.I. Pigment Red 194;-   perylene pigments: C.I. Pigment Black 31 and 32;-   C.I. Pigment Red 123, 149, 178, 179, 190, and 224;-   C.I. Pigment Violet 29;-   phthalocyanine pigments: C.I. Pigment Blue 15, 15:1, 15:2, 15:3,    15:4, 15:6, and 16;-   C.I. Pigment Green 7 and 36;-   pyranthrone pigments: C.I. Pigment Orange 51;-   C.I. Pigment Red 216;    pyrazoloquinazolone pigments:-   C.I. Pigment Orange 67;-   C.I. Pigment Red 251;-   thioindigo pigments: C.I. Pigment Red 88 and 181;-   C.I. Pigment Violet 38;    triarylcarbonium pigments:-   C.I. Pigment Blue 1, 61, and 62;-   C.I. Pigment Green 1;-   C.I. Pigment Red 81, 81:1, and 169;-   C.I. Pigment Violet 1, 2, 3, and 27;-   C.I. Pigment Black 1 (aniline black);-   C.I. Pigment Yellow 101 (aldazine yellow);-   C.I. Pigment Brown 22.

Examples of suitable inorganic color pigments include the following:

-   white pigments: titanium dioxide (C.I. Pigment White 6), zinc white,    pigmentary zinc oxide; zinc sulfide,    lithopones;-   black pigments: black iron oxide (C.I. Pigment Black 11), iron    manganese black, spinel black (C.I. Pigment Black 27); carbon black    (CA. Pigment Black 7);    chromatic pigments:-   chromium oxide, chromium oxide hydrate green; chromium green (C.1.    Pigment Green 48); cobalt green (C.I. Pigment Green 50);-   ultramarine green; cobalt blue (C.I. Pigment Blue 28 and 36; C.I.    Pigment Blue 72); ultramarine blue; manganese blue;-   ultramarine violet; cobalt and manganese violet; red iron oxide    (C.I. Pigment Red 101);-   cadmium sulfoselenide (C.I. Pigment Red 108); cerium sulfide (C.I.    Pigment Red 265); molybdate red (C.I. Pigment Red 104); ultramarine    red-   brown iron oxide (C.I. Pigment Brown 6 and 7), mixed brown, spinel    phases and corundum phases (C.I. Pigment Brown 29, 31, 33, 34, 35,    37, 39, and 40), chrome titanium yellow (C.I. Pigment Brown 24),-   chrome orange; cerium sulfide (C.I. Pigment Orange 75);-   yellow iron oxide (C.I. Pigment Yellow 42); nickel titanium yellow    (C.I. Pigment Yellow 53; C.I. Pigment Yellow 157, 158, 159, 160,161,    162, 163, 164, and 189);-   chrome titanium yellow; spinel phases (C.I. Pigment Yellow 119);    cadmium sulfide and cadmium zinc sulfide (C.I. Pigment Yellow 37 and    35); chromium yellow (C.I. Pigment Yellow 34); bismuth vanadate    (C.I. Pigment Yellow 184).-   cerium sulfide (C.I. Pigment Red 265);-   molybdate red (C.I. Pigment Red 104); ultramarine red.

Particular preference is given as pigment P to a yellow, cyan, magentaor black pigment.

Examples of inorganic pigments used typically as fillers includetransparent silicon dioxide, finely ground quartz, aluminum oxide,aluminum hydroxide, natural micas, natural and precipitated chalk, andbarium sulfate.

Also suitable are luster pigments, which are platelet-shaped pigments ofsingle-phase or multi-phase construction whose color play ischaracterized by the interplay of interference, reflection, andabsorption phenomena. Examples include aluminum flakes and alsoaluminum, iron oxide, and mica flakes that are coated one or more times,more particularly with metal oxides.

The average particle size d₅₀ of the pigments P is preferably situatedat a value between 50 and 500 nm, more particularly between 70 nm and200 nm, more preferably between 70 and 150 nm.

The polymerizable wax D is preferably a reaction product of a polyol,long-chain aliphatic carboxylic acids, and at least one ethylenicallyunsaturated carboxylic acid, and may have been oligomerized by theaddition of a dicarboxylic acid. Long-chain aliphatic carboxylic acidswhich can be used include all carboxylic acids having more than 7 carbonatoms, but preferably C₈-C₂₂ fatty acids and C₂₂-C₅₀ wax acids, eitherin pure form or else, preferably, in the form of mixtures of technicalproducts such as, for example, coconut fatty acid, tallow fatty acid,sunflower acid, montan wax acid, paraffin oxidate or olefin oxidate. Thecomposition of the mixture of acids is usually such that the meltingpoint of the mixture is above 50° C. For molecular weight enlargement,the mixtures of the long-chain carboxylic acids may also have beenadmixed with small fractions of dicarboxylic acids such as adipic acid,dodecanedioic acid, and montan wax dicarboxylic acids.

Polyols which can be used include polyhydric aliphatic alcohols having 2to 10 carbon atoms and 2 to 10 OH groups, such as glycols, glycerol,trimethylolpropane, glycerol, pentaerythritol, sugar alcohols, sorbitol,and their internal ethers such as sorbitans, their oligomers such asdiglycerol, dipentaerythritol, their polymers such as polyglycols orpolyglycerols, or the alkoxylates of the stated polyols.

As ethylenically unsaturated carboxylic acids it is possible for exampleto use acrylic acid, methacrylic acid, maleic acid, fumaric acid oritaconic acid, and also their anhydrides or esters. The stoichiometry ischosen such that one mole of polyol fatty acid partial ester is reactedwith one mole of the unsaturated carboxylic acid.

The polymerizable wax D may be illustrated by way of example using thereaction product of pentaerythritol, a mixture of long-chain aliphaticcarboxylic acids, based on technical montan wax acid, and acrylic acid:

R_(n)═H, CO—R_(m), R_(m)=alkyl radical of the montan wax acid

The polymerizable wax D can be prepared by reacting the polyol with thelong-chain aliphatic carboxylic acid to give a partial ester, which canthen be further reacted to a polyester wax by esterification with adicarboxylic acid. An ethylenically unsaturated acid is then attached tothis partial ester component via esterification, giving a solid reactiveproduct having a melting point between 40 and 90° C. Reactive compoundsof this kind are known and are available commercially, for example,under the name ®Licomont ER 165 (Clariant).

Used as monomer B are compounds which are able to react with theethylenically unsaturated functional group of the coating component D.Particularly suitable compounds in this group are acrylic acid,methacrylic acid, esters of acrylic acid, especially methyl acrylate,ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyalkylacrylates, acrylates of polyols, esters of methacrylic acid, especiallymethyl methacrylate, and hydroxyalkyl esters, and polyol esters. Use isalso made of styrene, alkylstyrenes, and divinylbenzenes.

The polymer a) of the invention is composed essentially of 5% to 95%,preferably 20% to 70%, more particularly 30% to 60%, by weight, ofpigment P, of 2.5% to 50%, preferably 5% to 40%, more particularly 10%to 30%, by weight, of the wax D reacted with monomer B, and of 2.5% to50%, preferably 5% to 40%, more particularly 10% to 30%, by weight ofthe monomer B reacted with D.

As additive E the polymer dispersions of the invention comprise at leastone nonionic surface-active additive based on polyethers orpolyglycerols. The polyethers are, more particularly, polyalkyleneoxides or reaction products of alkylene oxides with alcohols, amines,aliphatic carboxylic acids or aliphatic carboxamides. In accordance withthe invention, this term “alkylene oxide” should also be understood toinclude aryl-substituted alkylene oxide, more particularlyphenyl-substituted ethylene oxide. Besides the unmixed polyalkyleneoxides, preferably C₂-C₄ alkylene oxides and phenyl-substituted C₂-C₄alkylene oxides, more particularly polyethylene oxides, polypropyleneoxides, and poly(phenylethylene oxides), suitability is possessedprincipally by alkylene oxide block copolymers, but also by randomcopolymers of these alkylene oxides. Especially suitable in this contextare block copolymers which contain polypropylene oxide and polyethyleneoxide blocks or else poly(phenylethylene oxide) and polyethylene oxideblocks. Like the unmixed polyalkylene oxides, they can be obtained bypolyaddition of the alkylene oxides with starter compounds such assaturated or unsaturated aliphatic and aromatic alcohols, saturated orunsaturated aliphatic and aliphatic amines, saturated or unsaturatedaliphatic carboxylic acids and carboxamides. When using ethylene oxideand propylene oxide, these starter compounds can be reacted first withethylene oxide and then with propylene oxide, or first with propyleneoxide and then with ethylene oxide. Typically 1 to 300 mol, preferably 3to 150 mol, of alkylene oxide are used per mole of starter molecule.Suitable aliphatic alcohols in this context contain generally 6 to 26 Catoms, preferably 8 to 18 C atoms, and may be unbranched, branched orcyclic in construction. Examples include octanol, nonanol, decanol,isodecanol, undecanol, dodecanol, 2-butyloctanol, tridecanol,isotridecanol, tetradecanol, pentadecanol, hexadecanol, 2-hexyldecanol,heptadecanol, octadecanol, 2-heptylundecanol, 2-octyldecanol,2-nonyltridecanol, 2-decyltetradecanol, oleyl alcohol, and9-octadecenol, and also mixtures of these alcohols such as C₁₂/C₁₀,C₁₃/C₁₅ and C₁₆/C₁₈ alcohols, and cyclopentanol and cyclohexanol. Ofparticular interest are the saturated and unsaturated fatty alcoholswhich are obtained by fat cleavage and reduction from natural rawmaterials, and the synthetic fatty alcohols from the oxo process. Thealkylene oxide adducts of these alcohols typically have averagemolecular weights Mn of 200 to 5000, principally of 400 to 2000.

Examples of the abovementioned aromatic alcohols, as well as alpha- andβ-naphthol and their alkyl derivatives, include, in particular, phenoland its alkyl derivatives, such as hexylphenol, heptylphenol,octylphenol, nonylphenol, isononylphenol, undecyiphenol, dodecylphenol,di- and tributylphenol, and dinonylphenol.

Suitable aliphatic amines correspond to the aliphatic alcohols set outabove. Here again, particular importance is possessed by the saturatedand unsaturated fatty amines which contain preferably 14 to 20 C atoms.Examples of aromatic amines include aniline and its derivatives.Suitable aliphatic carboxylic acids are, in particular, saturated andunsaturated fatty acids which contain preferably 14 to 20 C atoms, andhydrogenated, part-hydrogenated and unhydrogenated resin acids, and alsopolyfunctional carboxylic acids, examples being dicarboxylic acids, suchas maleic acid.

Suitable carboxamides derived from these carboxylic acids.

Besides the alkylene oxide adducts of these monofunctional amines andalcohols, the alkylene oxide adducts of at least difunctional amines andalcohols are of very particular interest.

Preferred at least difunctional amines are amines with a functionalityof two to five which conform in particular to the formula H₂N—(R—NR¹)n-H(R: alkylene; R¹: hydrogen or C₁-C₆ alkyl; n: 1 to 5). Specific examplesthat may be mentioned include the following: ethylenediamine,diethylenetriamine, triethylenetetramine, tetraethylenepentamine,propylene-1,3-diamine, dipropylenetriamine,3-amino-1-ethylenaminopropane, hexamethylenediamine,dihexamethylenetriamine, 1,6-bis(3-aminopropylamino)hexane, andN-methyldipropylenetriamine, particular preference being given tohexamethylenediamine and diethylenetriamine, and very particularpreference to ethylenediamine. These amines are preferably reacted firstwith propylene oxide and then with ethylene oxide. The ethylene oxidecontent of the block copolymers is typically about 10% to 90% by weight.The block copolymers based on polyfunctional amines generally haveaverage molecular weights Mn of 1000 to 40 000, preferably 1500 to 30000.

Preferred at least difunctional alcohols are alcohols having afunctionality of two to five. Examples include C₂-C₃ alkylene glycolsand the corresponding di- and polyalkylene glycols, such as ethyleneglycol, propylene 1,2- and 1,3-glycol, butylene 1,2- and 1,4-glycol,hexylene 1,6-glycol, dipropylene glycol and polyethylene glycol,glycerol and pentaerythritol, particular preference being given toethylene glycol and polyethylene glycol, and very particular preferenceto propylene glycol and dipropylene glycol.

Particularly preferred alkylene oxide adducts of at least difunctionalalcohols have a central polypropylene oxide block, in other words startfrom a propylene glycol or polypropylene glycol, which is reacted firstwith further propylene oxide and then with ethylene oxide. The ethyleneoxide content of the block copolymers is typically 10% to 90% by weight.

The block copolymers based on polyhydric alcohols generally have averagemolecular weights Mn of 1000 to 20 000, preferably 1000 to 15 000.

Alkylene oxide block copolymers of this kind are known and are availablecommercially, for example, under the names Tetronic® and Pluronic®(BASF). Alkylene oxide block copolymers with different HLB(hydrophilic-lipophilic balance) values are selected as a function ofthe application medium in which the pigment preparations of theinvention are to be used.

Thus, for use in aqueous, aqueous/alcoholic, and alcoholic systems,alkylene oxide block copolymers with HLB values of approximately 10 arepreferred, corresponding to an ethylene oxide fraction in the copolymerof generally 25% by weight.

The polyglycerols are, more particularly, glycerides of fatty acids,such as polyglycerol polyricinoleate.

As additive F the polymer dispersions of the invention comprise at leastone anionic surface-active additive based on sulfonates, sulfates,carboxylates, phosphonates or phosphates. Examples of suitablesulfonates are aromatic sulfonates, such asp-C₃-C₉-alkylbenzenesulfonates, di(C₁-C₈-alkyl)naphthalenesulfonates,and condensation products of naphthalenesulfonic acids withformaldehyde, and aliphatic sulfonates, such as C₁₃-C₁₈alkanesulfonates, alpha-sulfo-fatty acid C₂-C₈ alkyl esters,sulfosuccinic esters, and alkoxy-, acyloxy-, andacylaminoalkane-sulfonates.

Alkylsulfonates are preferred, the di(C₁-C₈-alkyl)naphthalenesulfonatesbeing particularly preferred. Very particular preference is given todiisobutyl- and diisopropylnaphthalene-sulfonate. Examples of suitablesulfates are C₈-C₁₁ alkyl sulfates.

A further important group of anionic additives is formed by thesulfonates, sulfates, phosphonates, and phosphates of the polyethersspecified as nonionic additives. They can be converted, by reaction withphosphoric acid, phosphorous pentoxide, and phosphonic acid, or sulfuricacid and sulfonic acid, into the phosphoric monoesters or diesters andphosphonic esters, or into the sulfuric monoesters and sulfonic esters.Like the sulfonates and sulfates listed earlier on above, these acidicesters are preferably in the form of water-soluble salts, moreparticularly alkali metal salts, principally sodium salts and ammoniumsalts, but can also be used in the form of the free acids.

Preferred phosphates and phosphonates derive principally fromalkoxylated, more particularly ethoxylated, fatty alcohols andoxo-process alcohols, alkylphenols, stearylphenols, fatty amines, fattyacids, and resin acids; preferred sulfates and sulfonates are based moreparticularly on alkoxylated, especially ethoxylated, fatty alcohols,alkylphenols, and amines, including polyfunctional amines, such ashexamethylenediamine.

Anionic surface-active additives of this kind are known and areavailable commercially, for example, under the names Nekal® (BASF),Tamol® (BASF), Crodafos® (Croda), Rhodafac® (Rhodia), Maphos® (BASF),Texapon® (Cognis), Empicol® (Albright & Wilson), Matexil® (ICI),Soprophor® (Rhodia), Lutensit® (BASF), and Dispersogen (Clariant).

Examples of typical auxiliaries (e) are preservatives, pH regulators,thickeners, retention agents, and defoamers.

A variety of processes can be used for preparing the polymer dispersionsof the invention:

Process 1 comprises subjecting the pigment P in aqueous suspension tofine division with at least one part of the components b) and c), underthe action of shearing forces, homogenizing the thus prepared pigmentdispersion with the polymerizable wax D, optionally a part of monomer B,and optionally with addition of further component b) and/or c) at atemperature above the softening point of D, adding a mixture of water,monomer B, and optionally further component c) and/or d) to the coatedpigment dispersion thus prepared, and carrying out polymerization.

For the polymerization a typical polymerization initiator is optionallyadded, the mixture is brought to a temperature between 70 and 90° C.,and, optionally, further monomer B is metered in.

Process 2 comprises preparing a miniemulsion from the meltedpolymerizable wax D and components b) and c), then subjecting saidminiemulsion, together with an aqueous suspension of the pigment P, tofine division, under the action of shearing forces, adding a mixture ofwater, monomer B, and optionally further component b) and/or c) to thecoated pigment dispersion thus prepared, and carrying outpolymerization.

For the polymerization a typical polymerization initiator is optionallyadded, the mixture is brought to a temperature between 70 and 90° C.,and, optionally, further monomer B is metered in.

In one preferred embodiment of process 1, the pigment is first subjectedin aqueous suspension to wet comminution with at least one part of theadditive E and E The pigment dispersion thus prepared is dispersed withliquid wax D, optionally a portion of monomer B, and further additives Eand F at temperatures above the melting point of the wax. For thedispersing it is possible to use open vessels with simple stirringassemblies, though it is also possible to use dispersers of the kindknown from paint production, high-pressure homogenizers or otherpressure mixing chamber methods (vortex). In the course of thistreatment the liquid wax goes onto the pigment, and the coated particlesare stabilized by the additives E and F. The result is a coated pigmentdispersion.

A polymerization reactor is charged with water and emulsifiers from thegroup of additives F, and a portion of the monomers B, and this initialcharge is heated to about 70 to 80° C., then an initiator is added, andthe mixture is heated to 75 to 90° C. After the start of the reaction,remaining monomer B is metered in. The coated pigment dispersionindicated above is then metered into the reaction mixture. Following theaddition, further monomer B may be metered in. After the reaction theproduct is cooled, the pH is adjusted to neutral, and preservative isadded.

In one preferred embodiment of process 2, a miniemulsion is firstprepared from the melted wax D and additives of groups E and F, andafter cooling this miniemulsion is then admixed with further additives Eand F and is subjected to a wet comminution together with an aqueoussuspension of the pigment. In the case of this process, the wax isapplied to the pigment particles by grinding. The result is a coatedpigment dispersion.

A polymerization reactor is charged with water and emulsifiers from thegroup of additives F, and a portion of the monomers B, and this initialcharge is heated to about 70 to 80° C., then an initiator is added, andthe mixture is heated to 75 to 90° C. After the start of the reaction,remaining monomer B is metered in. The coated pigment dispersionindicated above is then metered into the reaction mixture. Following theaddition, further monomer B may be metered in. After the reaction theproduct is cooled, the pH is adjusted to neutral, and preservative isadded.

Initiators used are organic or inorganic free-radical initiators.Preference is given to using water-soluble inorganic initiators such asammonium peroxodisulfate or sodium peroxodisulfate, though organicinitiators such as AIBN or organic peroxides are likewise suitable.

In the case of peroxodisulfate initiators, a temperature of about 80° C.is optimal for the reaction; in the case of organic peroxides, thetemperature is adapted to the optimum of the initiator.

Both processes result in a polymer dispersion in which the pigmentparticles are incorporated chemically into the polymer via the readilyadhering, solid wax layer, and in which the particles are stabilized bythe additives E and F.

Polymer dispersions thus prepared are highly compatible with the typicalwater-based coating materials or inks. They can therefore be added as acoloring component at high pigment levels. Alternatively, depending onthe formulated film-forming temperature of the polymer mixture, they canbe used directly to form coatings or, in dilution with water andauxiliaries, can be used as inks in various printing processes.

The invention therefore also provides for the use of the polymerdispersion of the invention for coloring aqueous coating materials,varnishes, emulsion paints, printing inks and liquid inks, moreparticularly ink-jet inks, preferably for coloring paper, wood, andleather.

From the dispersions of the invention it is also possible, by removingthe solvent and carrying out drying, spray drying for example, toproduce colored polymer particles.

The invention accordingly also provides colored polymer particlescomposed _(—) 30 essentially of 5% to 95% by weight of pigment and of apolymerized coating prepared by polymerizing 2.5% to 50% by weight of apolymerizable wax D, in which the polymerizable function is anethylenically unsaturated group, with 2.5% to 50% by weight of a monomerB having a functional group which is able to react with theethylenically unsaturated group of D, the weight percentages being basedin each case on the total weight of the coated pigment particles, andthe sum of the weight percentages not exceeding 100% by weight, thepolymerizable wax D being a reaction product of a polyol, long-chainaliphatic carboxylic acids, and at least one ethylenically unsaturatedcarboxylic acid, and having possibly been oligomerized by the additionof a dicarboxylic acid.

Depending on the nature of the working up and drying, there may alsostill be 0% to 20% by weight of the nonionic additives b) and/or of theanionic additives c) and also further customary auxiliaries, such aspreservatives, present on the colored polymer particles.

The polymer particles of the invention are used as colorants moreparticularly in powder coating materials, UV-curing varnishes,electrophotographic toners and developers, in ink-jet inks, moreparticularly those with an aqueous or nonaqueous basis, in microemulsioninks and in hot-melt ink-jet inks.

Microemulsion inks are based on organic solvents, water, and, ifdesired, an additional hydrotropic substance (interface mediator).

Microemulsion inks contain generally 0.5% to 30% by weight, preferably1% to 15% by weight, of the polymer particles of the invention, 5% to99% by weight of water, and 0.5% to 94.5% by weight of organic solventand/or hydrotropic compound.

“Solvent based” ink-jet inks contain preferably 0.5% to 30% by weight ofthe polymer particles of the invention, 85% to 99.5% by weight oforganic solvent and/or hydrotropic compounds.

Hot-melt inks are based mostly on waxes, fatty acids, fatty alcohols orsulfonamides which are solid at room temperature and become liquid onheating, the preferred melting range being between about 60° C. andabout 140° C. Hot-melt ink-jet inks are composed, for example,essentially of 20% to 90% by weight of wax and 1% to 10% by weight ofthe polymer particles of the invention. Additionally present may be 0%to 20% by weight of an additional polymer, up to 5% by weight ofdispersing assistants, 0% to 20% by weight of viscosity modifiers, 0% to20% by weight of plasticizers, 0% to 10% by weight of tack additive, 0%to 10% by weight of transparency stabilizer (prevents, for example,crystallization of the waxes) and 0% to 2% by weight of antioxidant.

In the ink-jet inks the polymer particles of the invention may also beshaded with other colorants such as, for example, organic or inorganicpigments and/or dyes. In this case they are used in ink sets, consistingof yellow, magenta, cyan, and black inks, comprising pigments and/ordyes as colorants. Additionally they can be used in ink sets whichfurther comprise one or more “spot colors” in, for example, orange,green, blue, gold and silver colors.

Preference is given in this context to a set of printing inks whoseblack formulation comprises preferably carbon black as colorant, moreparticularly a gas black or furnace black; whose cyan formulationcomprises preferably a pigment from the group of the phthalocyanine,indanthrone or triarylcarbonium pigments, more particularly the ColourIndex pigments Pigment Blue 15, Pigment Blue 15:1, Pigment Blue 15:2,Pigment Blue 15:3, Pigment Blue 15:4, Pigment Blue 16, Pigment Blue 56,Pigment Blue 60 or Pigment Blue 61; whose magenta formulation comprisespreferably a pigment from the group of monoazo, disazo, naphthol,naphthol AS, laked azo, metal complex, benzimidazolone, anthanthrone,anthraquinone, quinacridone, dioxazine, perylene, thioindigo,triarylcarbonium or diketopyrrolopyrrole pigments, more particularly theColour Index pigments Pigment Red 2, Pigment Red 3, Pigment Red 4,Pigment Red 5, Pigment Red 9, Pigment Red 12, Pigment Red 14, PigmentRed 38, Pigment Red 48:2, Pigment Red 48:3, Pigment Red 48:4, PigmentRed 53:1, Pigment Red 57:1, Pigment Red 112, Pigment Red 122, PigmentRed 144, Pigment Red 146, Pigment Red 147, Pigment Red 149, Pigment Red168, Pigment Red 169, Pigment Red 170, Pigment Red 175, Pigment Red 176,Pigment Red 177, Pigment Red 179, Pigment Red 181, Pigment Red 184,Pigment Red 185, Pigment Red 187, Pigment Red 188, Pigment Red 207,Pigment Red 208, Pigment Red 209, Pigment Red 210, Pigment Red 214,Pigment Red 242, Pigment Red 247, Pigment Red 253, Pigment Red 254,Pigment Red 255, Pigment Red 256, Pigment Red 257, Pigment Red 262,Pigment Red 263, Pigment Red 264, Pigment Red 266, Pigment Red 269,Pigment Red 270, Pigment Red 272, Pigment Red 274, Pigment Violet 19,Pigment Violet 23 or Pigment Violet 32; whose yellow formulationcomprises preferably a pigment from the group of the monoazo, disazo,benzimidazoline, isoindolinone, isoindoline or perinone pigments, moreparticularly the Colour Index pigments Pigment Yellow 1, Pigment Yellow3, Pigment Yellow 12, Pigment Yellow 13, Pigment Yellow 14, PigmentYellow 16, Pigment Yellow 17, Pigment Yellow 73, Pigment Yellow 74,Pigment Yellow 81, Pigment Yellow 83, Pigment Yellow 87, Pigment Yellow97, Pigment

Yellow 111, Pigment Yellow 120, Pigment Yellow 126, Pigment Yellow 127,Pigment Yellow 128, Pigment Yellow 139, Pigment Yellow 151, PigmentYellow 154, Pigment Yellow 155, Pigment Yellow 173, Pigment Yellow 174,Pigment Yellow 175, Pigment Yellow 176, Pigment Yellow 180, PigmentYellow 181, Pigment Yellow 191, Pigment Yellow 194, Pigment Yellow 196,Pigment Yellow 213 or Pigment Yellow 219; whose orange formulationcomprises preferably a pigment from the group of the disazo, β-naphthol,naphthol AS, benzimidazolone or perinone pigments, more particularly theColour Index pigments Pigment Orange 5, Pigment Orange 13, PigmentOrange 34, Pigment Orange 36, Pigment Orange 38, Pigment Orange 43,Pigment Orange 62, Pigment Orange 68, Pigment Orange 70, Pigment Orange71, Pigment Orange 72, Pigment Orange 73, Pigment Orange 74 or PigmentOrange 81; and whose green preparation comprises preferably a pigmentfrom the group of the phthalocyanine pigments, more particularly theColour Index pigments Pigment Green 7 or Pigment Green 36.

In addition it is possible for the ink sets further to comprise shadingdyes, preferably from the group of C.I. Acid Yellow 17 and C.I. AcidYellow 23; C.I. Direct Yellow 86, C.I. Direct Yellow 98, and C.I. DirectYellow 132; C.I. Reactive Yellow 37; C.I. Pigment Yellow 17, C.I.Pigment Yellow 74, C.I. Pigment Yellow 83, C.I. Pigment Yellow 97, C.I.Pigment Yellow 120, C.I. Pigment Yellow 139, C.I. Pigment Yellow 151,C.I. Pigment Yellow 155 and C.I. Pigment Yellow 180; C.I. Direct Red 1,C.I. Direct Red 11, C.I. Direct Red 37, C.I. Direct Red 62, C.I. DirectRed 75, C.I. Direct Red 81, C.I. Direct Red 87, C.I. Direct Red 89, C.I.Direct Red 95 and C.I. Direct Red 227; CA. Acid Red 1, C.I. Acid Red 8,C.I. Acid Red 80, C.I. Acid Red 81, C.I. Acid Red 82, C.I. Acid Red 87,C.I. Acid Red 94, C.I. Acid Red 115, C.I. Acid Red 131, C.I. Acid Red144, C.I. Acid Red 152, C.I. Acid Red 154, C.I. Acid Red 186, C.I. AcidRed 245, C.I. Acid Red 249 and C.I. Acid Red 289; C.I. Reactive Red 21,C.I. Reactive Red 22, C.I. Reactive Red 23, C.I. Reactive Red 35, C.I.Reactive Red 63, C.I. Reactive Red 106, C.I. Reactive Red 107, C.I.Reactive Red 112, C.I. Reactive Red 113, C.I. Reactive Red 114, C.I.Reactive Red 126, C.I. Reactive Red 127, C.I. Reactive Red 128, C.I.Reactive Red 129, C.I. Reactive Red 130, C.I. Reactive Red 131, C.I.Reactive Red 137, C.I. Reactive Red 160, C.I. Reactive Red 161, C.I.Reactive Red 174, and C.I. Reactive Red 180.

The polymer particles of the invention are suitable for producing inksfor use in all conventional ink-jet printers, more particularly forthose which are based on the bubble-jet or piezo process.

The polymer particles of the invention are also suitable for use ascolorants in electrophotographic toners and developers, such as one- ortwo-component powder toners (also called one- or two-componentdevelopers), magnetic toners, liquid toners, polymerization toners, andspecialty toners, for example. Typical toner binders areaddition-polymerization resins, polyaddition resins, andpolycondensation resins, such as styrene, styrene acrylate, styrenebutadiene, acrylate, polyester, and phenol-epoxy resins, polysulfones,polyurethanes, individually or in combination, and also polyethylene andpolypropylene, which may also have further ingredients, such as chargecontrol agents, waxes or flow assistants, present in them or addedsubsequently to them for modification.

The polymer particles of the invention are additionally suitable for useas colorants in powders and powder coating materials, more particularlyin triboelectrically or electrokinetically sprayable powder coatingmaterials which are employed for the surface coating of articles made,for example, from metal, wood, plastic, glass, ceramic, concrete,leather, textile material, paper or rubber.

General procedure for Examples 1 to 10 (process 1):

(a) Preparation of a Pigment Dispersion:

The pigment, in the form either of a powder or a filter cake, is pastedin deionized water together with the dispersants, the organic solvent,and the other additions, and then the paste is homogenized andpredispersed using a dissolver or other suitable apparatus. Thesubsequent fine dispersion takes place by means of a bead mill (e.g.,with a MiniZETA 03 from Netzsch) or other suitable dispersing assembly,with grinding taking place accompanied by cooling and proceeding untilthe desired size distribution of the pigment particles is obtained.Thereafter the dispersion is adjusted with deionized water to thedesired final pigment concentration.

(b) Preparation of a Wax-Coated Pigment Dispersion:

Polymerizable wax D (e.g. ®Licomont ER 165 with AN: 10.0) is melted withslow stirring in a glass vessel at a temperature of around 120° C.Nonionic surfactant (additive E) and anionic surfactant (additive F) aredissolved in a solvent (e.g., 1,2-propylene glycol) at 90° C. in asecond vessel and the solution is admixed with KOH.

The emulsifier mixture formed is stirred into the wax melt atapproximately 100-120° C. with thorough stirring. The resulting melt ispoured slowly into the pigment dispersion (a), which has been brought toabout 90° C., and the mixture is stirred further at this temperature fora short time. Subsequently the further additives (e.g., preservative)are added.

(c) Polymerization with Monomer B:

Water, anionic surfactant (neutralized), and 15% of the monomer mixtureB1 are charged to a reactor and heated to about 75° C. Ammoniumperoxodisulfate is dissolved in demineralized water and added to thereaction mixture. The mixture is heated to 80° C. Following the onset ofthe reaction, the remaining monomer mixture B1 is metered into thereactor over 1 h. Thereafter, over 30 to 45 min, the wax-coated pigmentdispersion from (b) is incorporated at a temperature above 78° C.Subsequently, monomer mixture B2 is metered at 80° C. and the mixture isstirred at this temperature for 2 h. Unreacted monomer is removed bydistillation and the reaction mixture is cooled to below 35° C. Ascorbicacid and H₂O₂ are added, the mixture is stirred for 30 min, preservativeis added, and the pH is adjusted to 7 by addition of KOH. This isfollowed by filtration through a 50 pm filter.

EXAMPLES 1 to 5

a) Preparation of a PY 155 Pigment Dispersion:

C.I. Pigment Yellow 155 20 Nonionic surfactant 10 Anionic surfactant 2® Mergal K7 0.1 ® Mergal K10N 0.1 1,2-Propylene glycol 10 Water 57.8

b) Preparation of a Wax-Coated PY 155 Pigment Dispersion:

® Licomont ER 165 240 Anionic surfactant 16 Nonionic surfactant 34 KOH,43% strength 10 Water 300 Pigment dispersion from (a) 1800

Coating Pigment Emulsifier TSC % % % Type % Example 1: 10 15 2.3 1 28Example 2: 10 15 2.3 1 28 Example 3: 10 15 2.3 4 28 Example 4: 10 15 2.33 28 Example 5: 7 15.6 1.4 2 25

Emulsifier: nonionic+anionic surfactant

-   Nonionic surfactant: ®Genapol T 110,-   Anionic surfactant: Genapol LRO (Type 1),    -   ®Dispersogen LFES (Type 2),    -   Dispersogen LFH (Type 3),    -   Dispersogen T 160 (Type 4).

Genapol and Dispersogen are Clariant trademarks.

-   ®Licomont ER 165=pentaerythritol 2,5-montanate acrylate (Licomont is    a Clariant trademark);-   TSC=total solids content.

(c) Preparation of a Polymer Dispersion:

Wax-coated pigment dispersion PY 155 from (b): 450 Dispersogen LFH 28%strength 12.5 Monomer B1 20 Monomer B2 10 Ammonium peroxodisulfate 0.95Ascorbic acid 0.7 Water 400 H₂O₂, 35% strength 3.5 Preservative 0.3

-   Monomer B1: methyl methacrylate 9.4, ethyl acrylate 9.4, methacrylic    acid 1.2-   Monomer B2: methyl methacrylate 5, ethyl acrylate 5-   Solids content: 14-15%; pigment content: 7-8%; MFT about 25.

EXAMPLES 6 and 7

a) Preparation of a Pigment Red 122 Pigment Dispersion:

C.I. Pigment Red 122 20 Nonionic surfactant 10 Anionic surfactant 2Mergal K7 0.1 Mergal K10N 0.1 1,2-Propylene glycol 10 Water 57.8

b) Preparation of a Wax-Coated PR 122 Pigment Dispersion:

Licomont ER 165 240 Anionic surfactant 16 Nonionic surfactant 34 KOH 43%strength 10 Water 300 Pigment dispersion from (a): 1800

Coating Pigment Emulsifier TSC % % % Type % Example 6: 10 15 2.3 1 30Example 7: 10 15 2.3 4 30

-   Nonionic surfactant: Genapol T 110;-   Anionic surfactant: Genapol LRO (Type 1),    -   Dispersogen T 160 (Type 4).

(c) Preparation of a Polymer Dispersion:

Wax-coated pigment dispersion PR 122: 450 Dispersogen LFH 28% strength12.5 Monomer B1 40 Monomer B2 20 Ammonium peroxodisulfate 0.83 Ascorbicacid 0.7 Water 400 H₂O₂, 35% strength 3.5 Preservative 0.3

-   Monomer B1: methyl methacrylate 19.2, ethyl acrylate 18.8,    methacrylic acid 2-   Monomer B2: methyl methacrylate 9.9, ethyl acrylate 10.1-   Solids content: 18-19%; pigment content: 7-8%; MFT about 25.

EXAMPLE 8

(a) Preparation of a Pigment Blue 15:3 Pigment Dispersion:

C.I. Pigment Blue 15:3 20 Nonionic surfactant 10 Anionic surfactant 2Mergal K7 0.1 Mergal K10N 0.1 1,2-Propylene glycol 10 Water 57.8

(b) Preparation of a Wax-Coated PB 15:3 Pigment Dispersion:

Licomont ER 165 240 Anionic surfactant 16 Nonionic surfactant 34 KOH 43%strength 10 Water 300 Pigment dispersion from (a) 1800

-   Coating: 10%; pigment: 15%; emulsifier, type (1): 2.3%.

(c) Preparation of a Polymer Dispersion:

Wax-coated pigment dispersion PB 15:3: 450 Dispersogen LFES, 28%strength 25 Monomer B1 40 Monomer B2 70 Ammonium peroxodisulfate 0.83Ascorbic acid 0.7 Water 413 H₂O₂, 35% strength 3.5 Preservative 0.3

-   Monomer B1: methyl methacrylate 19.2, ethyl acrylate 5.2,    methacrylic acid 2.0-   Monomer B2: methyl methacrylate 34.65, ethyl acrylate 35.35-   Solids content: 22-23%; pigment content 6-7%; MFT about 22.

EXAMPLE 9

(a) Preparation of a Pigment Black 7 Pigment Dispersion

C.I. Pigment Black 7 20 Nonionic surfactant 10 Anionic surfactant 2Mergal K7 0.1 Mergal K10N 0.1 1,2-Propylene glycol 10 Water 57.8

(b) Preparation of a Wax-Coated Pigment Black 7 Pigment Dispersion:

Licomont ER 165 240 Anionic surfactant 16 Nonionic surfactant 34 KOH 43%strength 10 Water 300 Pigment dispersion from (a) 1800

-   Coating: 10%; pigment: 15%; emulsifier, type (1): 2.3%.

(c) Preparation of a Polymer Dispersion:

Wax-coated pigment dispersion PB 7: 450 Dispersogen LFH, 28% strength6.4 Monomer B1 15.4 Monomer B2 — Ammonium peroxodisulfate 0.60 Ascorbicacid 0.7 Water 413 H₂O₂, 35% strength 3.5 Preservative 0.3

-   Monomer B1: methyl methacrylate 8.95, butyl acrylate 5.2,    methacrylic acid 1.25-   Solids content: 10-11%; pigment content 6-7%.

EXAMPLE 10 PY 155

A portion of the monomers B is included in the wax coating. The amountof monomer used here is then no longer added in the subsequentpolymerization.

® Licomont ER 165 105 Anionic surfactant 6.6 Nonionic surfactant 14 KOH43% strength 2.9 Methyl methacrylate 42.7 Water 250 Pigment dispersionfrom Example 1(a) 1576 Preservative 2.1

Steps (b) and (c) take place in the same way as in Example 1.

EXAMPLE 11 Pigment Black 7

A portion of the monomers B is included in the wax coating. The amountof monomer used here is then no longer added in the subsequentpolymerization.

® Licomont ER 165 50.12 Anionic surfactant 3.12 Nonionic surfactant 6.67KOH 43% strength 1.4 Methyl methacrylate 10.15 Butyl acrylate 10.15Water 119 Pigment dispersion from Example 1(a) 1576 Preservative 1.2

Steps (b) and (c) take place in the same way as in Example 9.

General procedure for Examples 12 to 19 (process 2):

(a) Preparation of a Pigment Dispersion:

Analogous to the procedure described in process 1.

(b) Preparation of a Miniemulsion:

To prepare a wax miniemulsion, the polymerizable wax D in melted form isstirred into an aqueous solution of the nonionic and anionic surfactantsabove the melting temperature of the wax D, and dispersed ifappropriate, forming an oil-in-water emulsion.

(c) Preparation of a Wax-Coated Pigment Dispersion:

The miniemulsion prepared in (b) is admixed with remaining nonionic andanionic surfactant, and the pigment dispersion prepared in (a) ismetered in. A milling or dispersing assembly is used to grind the waxonto the pigment particles.

(d) Preparation of a Polymer Dispersion:

Analogous to the procedure described in process 1.

The polymer dispersions described in Examples 1 to 8 were prepared bythe procedure of process 2: Examples 12 to 19.

Use Examples:

(A) Printing Inks:

The polymer dispersions of the invention and also, for comparison, thecorresponding standard dispersions (steps a above) were incorporatedinto printing inks. Only in the case of the polymer dispersions of theinvention was it possible to prevent the ink striking through the paper.The resulting image was glossy and water-resistant. Images with thestandard dispersions were not water-resistant and showed virtually nogloss.

(B) Liquid Varnishes and Emulsion Paints:

The polymer dispersions of the invention and also, for comparison, thecorresponding standard dispersions (a) were incorporated into varnishesand emulsion paints. The paint coating with the polymer dispersions ofthe invention was substantially more water-resistant than with thestandard dispersions.

(C) Powder Coating Materials:

The polymer dispersions of the invention and also, for comparison, thecorresponding standard dispersions (a) were spray dried and incorporatedinto powder coating materials.

In the case of the inventive powder coating materials, the color yieldwas higher and the chemical fixing in the matrix after baking wassubstantially better than in the case of the standard powder coatingmaterials.

1-11.) (canceled) 12) Colored polymer particles comprising 5% to 95% byweight of pigment and a polymerized coating prepared by polymerizing2.5% to 50% by weight of a polymerizable wax D, in which thepolymerizable function is an ethylenically unsaturated group, with 2.5%to 50% by weight of a monomer B having a functional group which reactswith the ethylenically unsaturated group of D, the weight percentagesbeing based in each case on the total weight of the coated pigmentparticles, and the sum of the weight percentages not exceeding 100% byweight, wherein the polymerizable wax D being is a reaction product of apolyol, long-chain aliphatic carboxylic acids, and at least oneethylenically unsaturated carboxylic acid, and optionally, oligomerizedby the addition of a dicarboxylic acid. 13) A process for producingcolored polymer particles as claimed in claim 12, comprising the step offreeing a colored polymer dispersion from solvents and subjecting thepolymer dispersion to drying, wherein the colored polymer dispersioncomprises as essential constituents (a) a color polymer prepared bypolymerizing monomer A with monomer B, wherein monomer A is a pigment Pcoated with a polymerizable wax D and wherein the polymerizable functionis an ethylenically unsaturated group, and monomer B being anethylenically unsaturated compound; (b) at least one nonionicsurface-active additive E based on polyethers, polyglycerols or amixture thereof; (c) at least one anionic surface-active additive Fbased on sulfonates, sulfates, phosphonates, phosphates or carboxylates;(d) water. 14) A composition colored by the polymer particles as claimedin claim 12, wherein the composition is selected from the groupconsisting of ink-jet inks, powder coating materials, UV-curingvarnishes, electrophotographic toners, and electrophotographicdevelopers.